The overall objective of this program project in trauma is to continue to explore in depth, the clinical changes following severe bodily insult with the hope of providing a better rationale for the treatment and care of such patients. The progress since the last reoport may be emphasized from the evaluation of over fifty patients during the year for metabolic balance for nitrogen, calories and electrolytes. Many of these patients were further evaluated as to their (1) nutritional status using 3-Methylhistidine excretion, serum RNAse levels, creatinine excretion and muscle protein/DNA ratios, (2) carbohydrate metabolism using 14C-glucose, (3) gluconeogenic response in injury using 14C-L-alanine and (4) whole body protein synthesis in injury using 14N: 14C amino acids. Preliminary results show that skeletal trauma and severe sepsis elicit a large increase (3-5X) of muscle protein breakdown using 3-MEH as an indicator. Isotope studies show protein synthesis and catabolic rates are increased with catabolism predominating. 15N and 14C methods thus far appear to provide similar rates. Skeletal trauma appears to increase glucose metabolism but not to the extent as sepsis. An increased gluconeogenic response has been observed in sepsis and skeletal trauma which was not suppressed using exogenous infusions of glucose at the hepatic production rate. These studies will be continued in the coming year.